The two-and-one-half acres for the park was approved for that use and donated by the Donnells in 1847. The park is one block square, bordered by Lombard, Stricker, Gilmor, and Hollins streets. The landscape of Union Square – with its walkways, pavilion, fountain, and wrought iron lamps – recalls Victorian Era Baltimore. Architect John F. Hoss designed the iron Greek-style pavilion with fluted columns in 1850 – it covers a natural spring that was once accessible by steps and, at one time, supplied water to the B&O Railroad. The source of the name “Union Square” is uncertain but probably reflects the patriotic sentiment of this time before the Civil War. Fog scenes of the Square, lights agleam over wet pavements and barren limbs, were often featured in local landscape artistry.

 

The park and fountain – as well as parts of Stricker, Hollins and Lombard streets – were transported back to the 1850s when Union Square played the title role in the lush 1997 movie adaptation of Henry James's biting novel Washington Square from acclaimed director Agnieszka Holland.

The excitement continued in 1997 as the community celebrated the sesquicentennial of Union Square with a re-dedication of the park including the placement of a stone tablet commemorating the event at the foot of one of the pavilion columns. The celebration was highlighted with concerts and a marching band performance, and the dedication of a new park at Pratt and Gilmor streets.

 

Source: wikipedia.org/wiki/Union_Square,_Baltimore